1. Field of the Invention
The present invention relates to an image output system in which, for example, a computer, a print server and a printer are interconnected via a network.
2. Description of the Related Art
Recently, computers are interconnected via a LAN (local area network), and various peripheral apparatuses, such as a multifunctional image processing apparatus having copying and facsimile functions, and the like, can also be subjected to LAN connection.
A LAN through which computers within a location (for example, a floor of a building) are interconnected allows sharing of apparatuses by a user group and data transfer between the apparatuses. In some cases, by interconnecting a plurality of LANs present at geographically separated locations via a high-speed integrated digital network (such as an ISDN (Integrated Services Digital Network) or the like) or a public telephone network, a WAN (wide area network), such as the Internet WWW (World Wide Web), is provided.
Usually, such a LAN/WAN is constituted by computers including file servers and print servers. A network operating system mounted in each of the computers deals with various protocols, for example, for transferring data and files, sharing data and files, and sharing a printer.
A printing job transferred from application software operating in each computer is generally transferred to a printer connected to the network via a print server.
A communication protocol for performing remote control and acquiring information of various apparatuses constituting the network, such as computers and printers connected to the network, is standardized. The SNMP (Simple Network Management Protocol) is known as a typical example of such protocols.
When network apparatuses mount such a protocol, network management software can manage these apparatuses and acquire information from a remote location connected to the network. For example, in the case of a printer, it is possible, for example, to acquire information relating to the printer, monitor the state of the printer, notify that the state of the printer has changed, and control initialization of the printer.
Various sets of document formation software, table calculation software and the like are known as sets of user application software operating in each computer constituting a LAN. Data formed using such application software is converted into data of a PDL (Printer Description Language), serving as a printer control language, by printer driving software. The obtained PDL data is temporarily stored in a print spooler, and then transmitted to a printer as a printing job. A print spooler and a single printer are not always in one-to-one correspondence. In some cases, printing jobs stored in corresponding ones of a plurality of print spoolers are transmitted to a printer.
A printing job is generated by converting data generated from one or a plurality of application document files into PDL data corresponding to each printer by printer driver software, and is a unit constituting one printing document. Usually, a printing job is framed by a job starting instruction and a job ending instruction. The type of the PDL data and version information are added to the job starting instruction or the like. Such information is utilized for determining the type or the version of the PDL data by a printing-job processing module when a printing job is processed in the printer.
In a LAN, computers, printers and the like are usually interconnected by Ethernet cables. Recently, however, network interconnection of digital apparatuses according to the IEEE 1394-1995 (High Performance Serial Bus) method having a higher speed has also been realized.
Apparatuses, each having an IEEE 1394 serial bus interface (I/F), have respective peculiar IDs and constitute a network by mutually recognizing these IDs. Each of the apparatuses connected to the network can independently transmit data to another apparatus without intervention of a computer, and can sometimes receive data.
In the above-described conventional approach, a host computer can display a state of processing of a printing job within the computer's print spooler, such as in storage in a spool, in holding, in transfer, or the like, on a CRT (cathode-ray tube). However, it is impossible to acquire printing-job information relating to a printing job already transferred from the print spooler to an image output apparatus, and to display a state of processing of the job on the CRT.
In the conventional approach, a host computer can perform control of a schedule of a printing job within the computer's print spooler, such as temporary interruption of transfer of the printing job, cancel of the printing job, change of the order of transfer of the printing job, or the like, in accordance with an instruction from the user. However, it is impossible to directly control an output schedule of a printing job already transferred from the print spooler to an image output apparatus, or to provide the image output apparatus with an instruction of a schedule in order to change an output schedule.
In the conventional approach, since a host computer cannot acquire printing-job information relating to a printing job transferred from another print server or another input unit, it is impossible to control display of job information of a printing job transferred from another user within an image output apparatus, display of a state of processing of the printing job, and an output schedule of the printing job.
In the conventional approach, it is impossible to determine whether or not a printing job output from another user remains within an image output apparatus. Accordingly, when another user transfers a large amount of image data to another print spooler or from another input unit even if a printing job to be transferred is absent within a print spooler, it is necessary to await output of the data, resulting in an increase in the time for outputting a printing job.